When this species was first assessed in 2013, its identity was uncertain as material of three different species were included in the revision of Epirinus sulcipennis by Scholtz and Howden (1987). However, E. sulcipennis was described from "southern Caffraria and also Cape of Good Hope" and is considered to be closely related to E. validus, described from "Transvaal (Lydenburg)". Available material examined by Scholtz and Howden (1987) was re-examined by Davis et al. (2020). Specimens from 1,450 m on Grootberg (Western Cape) are considered to represent true E. sulcipennis, as their slightly ribbed elytra differ from the smooth elytra of E. validus (A. Davis pers. comm. 2023).

Material from Queenstown (80 km north) is dissimilar to both E. validus and E. sulcipennis and may represent an undescribed species close to E. striatus. Material cited by Scholtz and Howden (1987) from Knysna, Albany and Smithfield (Free State) was not available for re-examination but at least one locality (Smithfied) is close to the known range of E. validus to the northeast of the southern biased range of E. sulcipennis (A. Davis pers. comm. 2023).

Epirinus sulcipennis has been listed as Data Deficient as its taxonomic identity needs confirmation by re-examination of the lectotype together with more recently recorded specimens. Furthermore, of the material cited by Scholtz and Howden (1987) that was available, only specimens from a single locality are likely to be E. sulcipennis. Thus, at present, insufficient data exist on the range and habitat associations of this species, including the possible influence of natural versus transformed vegetation on its population dynamics. After confirmation of its identity, further research on its distribution and ecological associations is suggested to generate a more informed assessment of the conservation status and extinction risk to this species.

This species is represented by a lectotype from an inexact locality in the “Cape of Good Hope”. It is difficult to define a geographical range owing to the inclusion of more than one species in the series of specimens cited as Epirinus sulcipennis Boheman, 1857 in the most recent revision (Scholtz and Howden 1987). After examination of available material, only specimens from Grootberg in the Western Cape in South Africa currently qualify as bona fide records for this species, subject to confirmation by comparison with the type. It is likely that this species is restricted to southern coastal mountains of South Africa that receive spring, autumn and winter rainfall. The only confirmed record with precise data is from a locality at 1,450 m asl in the Swartberg (Grootberg). A further reported occurrence from a wet coastal area in Knysna requires validation (Davis et al. 2020), as does a record from Albany.

The limited data for this species suggest a low population density.

One confirmed record is from an area comprising natural shrubland and sandy soil, with mean annual rainfall 379 mm and mean annual temperature 10.9 °C (Davis et al. 2020). This locality lies in the North Langeberg Sandstone Fynbos vegetation region (Davis et al. 2020).

Although this species has been recorded from a region in which the natural vegetation is fynbos shrubland, the vegetation of origin was not recorded. Furthermore, it has not been determined if it is threatened by vegetation transformation but this seems unlikely as only 8% of the mountain fynbos around the single confirmed mountain locality has been transformed.

There is no use or trade information available for this species.

There are no species-specific conservation measures in place. In order to determine the conservation status and extinction risk of this species, a survey of mountain fynbos localities needs to be conducted to determine its range in the Western Cape, and to collect additional material in order to clarify its taxonomic status. As its close relative, Epirinus validus has been recently recorded in the coastal hills at Grahamstown (now Makhanda) (C. du Toit pers. comm.), it may be useful to make quantitative measurements from both natural and adjacent transformed vegetation to determine if vegetation transformation influences its conservation status